| Abstract: | To explore the relation of Interleukin-8 (IL8) gene polymorphism with immunity against mastitis in dairy cow, the polymorphism of IL8 gene was investigated in 610 Chinese Holstein cow from 30 bull families in a dairy farm in Shanghai using polymerase chain
reaction–single strand conformation polymorphism (PCR–SSCP) technique, and milk yield, milk fat percentage, milk protein percentage,
305 day corrected milk yield, 305 day milk fat yield, 305 day milk protein yield and somatic cell score (SCS) were measured
and analyzed, and the mRNA levels of IL8 genotypes in blood were detected by real-time PCR. The results showed that three genotypes, KK, KA and AA were detected with
frequencies of 0.187, 0.451, and 0.362, respectively. The gene frequencies of K and A were 0.412 and 0.588, respectively.
The significant association of the IL8 mutations with milk yield, 305 day milk protein yield, 305 day corrected milk yield and 305 day milk fat yield, SCS, and
significant association with milk protein percentage were identified, while their association with milk fat percentage were
not significant. KK had higher milk yield, 305 day milk protein yield, 305 day corrected milk yield and 305 day milk fat yield
than AA or KA, and the least square mean of SCS of KK was significantly lower than that of AA or KA. AA had significant lower
milk protein yield than KK or KA. The relative IL8 mRNA level of KK in blood was the highest. These findings demonstrated that IL8 genotype significantly correlated with mastitis resistance and the locus could be a useful genetic marker for mastitis resistance
selection and breeding in Chinese Holstein. |
